On my alluminium 15" PBook I've always used ctrl click to act like a right mouse secondary button, but thought I would try the 2-finger tap method and went into the Syst Pref/Trackpad menu to set it up. Although the trackpad gestures showed two-fingers to scroll, there was no option for 2-finger tackpad tap for secondary click. This was on my PBook5.4 (A1095) 1.33GHz (2004-5) model with Leopard 10.5.8. Reading up a number of different posts including THIS one from 2007, I installed iScroll2.032 which had no effect. I then thought to double check on another alluminium 15" PBook, my PB5.8 (A1138) 1.67GHz (2005-6 model) also with OS X 10.5.8, and was surprised to see an option in the trackpad setup menu for 'Tap trackpad using two fingers for secondary click'. On selecting this option, trackpad secondary click was functional. Can one conclude from this that the iScroll app is incompatible, and therefore no way to activate a 2 finger tap right click on these earlier (2004-5) PBooks?